Livestatus injection via monitoring filter values
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
Improper neutralization of newlines in filter values in the monitoring host and service list APIs in Checkmk <2.5.0p14 allows an authenticated user to inject additional Livestatus query headers, bypassing object visibility restrictions in count queries to infer information about hosts and services outside their contact groups and occupying web server and Livestatus workers for an attacker-controlled duration.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Checkmk GmbH | Checkmk | 2.5.0 to before 2.5.0p14 | 2.5.0p14 | Patch available | CNA |
- Checkmk VendorCheckmk GmbH Affected 2.5.0 to before 2.5.0p14 Fixed in 2.5.0p14 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:* | — | — | Checkmk GmbH |
- cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:* Versions — — ·Checkmk GmbH
Remediation
- Fix · CNA Checkmk (Checkmk GmbH) Fixed in 2.5.0p14
Timeline
- 2026-10-02 Threatist record created from CVE-2026-90990
- 2026-10-03 Alias added: GHSA-v742-5hjw-gqcp
References
Advisory 1
More Checkmk GmbH vulnerabilities
- TI-2025-26345 Cross Site Scripting through compromised remote site CVSS 4.0HIGH 8.5
- TI-2025-40190 Cross-site scripting in HTML logs of Synthetic Monitoring test services CVSS 4.0HIGH 7.3
- TI-2024-12762 Checkmk NagVis Remote Code Execution CVSS 3.1HIGH 7.2
- TI-2024-12761 Checkmk NagVis Reflected Cross-site Scripting CVSS 3.1MEDIUM 5.4
- TI-2024-19037 Brute-force protection ineffective for some login methods CVSS 3.1CRITICAL 9.8
- TI-2024-05712 local IP restriction of internal HTTP endpoints CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-90990 · CVE Program
- CVE-2026-90990 · NVD
- FIRST EPSS
- GHSA-v742-5hjw-gqcp · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences